View, edit, sign —
one PDF app does it all
Pomelo's PDF engine is its own — no off-the-shelf PDF library, and the whole app is only 318 KB. Contracts, forms and official documents: read them, then annotate, sign, edit text and remove watermarks without reaching for another program.
Chinese documents and encrypted files
open right away
- Documents without embedded fonts (PMingLiU, DFKai-SB) are shown with system fonts
- Vertical text and Big5-encoded font names work too
- Password-protected PDFs: RC4, AES-128, AES-256
- Damaged files: broken cross-reference tables are repaired automatically
- Scanned documents: CCITT, JPEG 2000 and JBIG2 images
- Search: all matches in yellow, the current one in orange; full-width letters and digits are found too
- Select text: double-click for a word, triple-click for a line, Ctrl+C to copy
- Multiple tabs, bookmarks and thumbnails; reopens at the page where you left off
- Print (Ctrl+P), full screen (F11), dark mode
Highlight, take notes,
and sign your name
- Highlight, underline, strikethrough: drag across the text
- Sticky notes and text: click once and start writing
- Pen, rectangles, ellipses, lines and arrows
- Choose colors and line widths; drag, resize or delete
- Handwritten signatures: sign with your mouse, or use a photo of your signature (white background removed automatically)
- Click a saved signature to place it, then drag and resize it
- Fill in text in the blanks of a form
- Changes are appended to the original file, so other PDF readers see them too
Prove "I signed this,
and nothing changed since"
Signing and verification are Pomelo's own code, using OpenSSL for the cryptography. Documents we sign are verified as valid by poppler.
- Sign with a digital ID (.p12/.pfx)
- Create your own ID, or import one issued by a certificate authority
- Add your handwritten signature to the appearance, plus a reason and location
- Click an empty signature field in the document to sign right there
- Add annotations after signing and the signature stays valid
- "View signed version" and "Trust this certificate"
Rotate, reorder, merge, number
Organize pages
Thumbnails of every page: rotate, delete, drag to reorder, extract into a new document, insert another PDF or a blank page.
Merge files
Combine several PDFs in order into one, with a bookmark for each file; the originals are left untouched.
Add page numbers
Six formats (e.g. "Page 1 of 9"), six positions, choose which page to start numbering from — skip the cover if you like.
Edit the original text on the page
Every line you can edit has a faint box around it. Click a line to edit; clear it to delete.
- New text uses the closest matching original font: Ming, Kai or Hei, and bold stays bold
- The rest of the line shifts to fit; edited text can be selected, searched and copied
- Add text: written directly into the page content — not an annotation others can delete
- Password-protected files keep the same encryption after editing
Watermarks, gone in one step
Finds everything in the document that might be a watermark and on how many pages it appears; the obvious ones are already ticked — confirm to remove them all at once.
- Content marked as watermarks, watermark layers and annotations
- Diagonal semi-transparent text or the same image on every page
- Headers and footers
Files it writes are readable by other PDF readers too
Checked with qpdf
Every saved file is checked with qpdf, and other PDF readers see the same annotations, signatures and page numbers.
Signatures verified with poppler
Documents signed by Pomelo are verified as valid by poppler (including encrypted ones); tampered documents show an invalid signature.
Fuzz testing
Deliberately broken PDFs can't make it eat all your memory or write out of bounds; drawing per page is capped.
Not yet possible: filling in form fields (coming in a later version), signing with certificates on smart-card readers (e.g. Taiwan's Citizen Digital Certificate), and adding timestamps when signing. Text is edited line by line without automatic rewrapping.